The spine includes a row of 26 bones in the back and allows a person to stand up straight and bend over. The spine also protects a person's spinal cord from being injured. In people with spinal stenosis, the spine is narrowed in one or more of three parts: (1) the space at the center of the spine; (2) the canals where nerves branch out from the spine; and (3) the space between vertebrae (the bones of the spine). This narrowing puts pressure on the spinal cord and nerves and can cause pain.
Caused by aging spinal stenosis is most common in men and women over 50 years old. Younger people who were born with a narrow spinal canal or who hurt their spines may also get spinal stenosis. Changes that occur in the spine as people get older are the most common cause of spinal stenosis such as: (a) the bands of tissue that support the spine may get thick and hard; (b) bones and joints may get bigger; and (c) surfaces of the bones may bulge out, which are called bone spurs.
In some cases arthritis, a degenerative condition, can cause spinal stenosis. Two forms of arthritis that may affect the spine are: (a) osteoarthritis and (b) rheumatoid arthritis.
Osteoarthritis is the most common form of arthritis and most often occurs in middle-aged and older people. It may involve many joints in the body where it wears away the tough tissue (cartilage) that keeps the joints in place and can cause bone spurs and problems with joints.
Rheumatoid Arthritis affects most people at a younger age than osteoarthritis. It causes the soft tissues of the joints to swell and can affect internal organs and systems. However, it is not a common cause of spinal stenosis but can cause severe damage, especially to joints.
Some people are born with conditions that cause spinal stenosis. For instance, some people are born with a small spinal canal. Others are born with a curved spine (scoliosis). Other causes of spinal stenosis are: tumors of the spine; injuries; Paget's disease (a disease that affects the bones); too much fluoride in the body; and calcium deposits on the ligaments that run along the spine.
In many cases there may be no symptoms of spinal stenosis, or symptoms may appear slowly and get worse over time. Signs of spinal stenosis include: pain in the neck or back; numbness, weakness, cramping, or pain in the arms or legs; pain going down the leg; and foot problems.
One type of spinal stenosis, cauda equine syndrome, is very serious. This type occurs when there is pressure on nerves in the lower back. Symptoms may include: loss of control of the bowel or bladder; problems having sex; and pain, weakness, or loss of feeling in one or both legs.
Because spinal stenosis has many causes and symptoms, treatment may be required from doctors who specialize in certain aspects of the condition. Health care providers can include: rheumatologists (doctors who treat arthritis and related disorders); neurologists and neurosurgeons (doctors who treat diseases of the nervous system); orthopedic surgeons (doctors who treat problems with the bones, joints, and ligaments); and physical therapists.
As people age the amount of adverse spinal conditions tend to increase. For example, increases in spinal stenosis, such as central canal and lateral stenosis, along with the thickening of the bones making up the spinal column and facet arthropathy are expected. Spinal stenosis typically includes a reduction in the available space for the passage of blood vessels and nerves which can impinge on these. Pain associated with such stenosis can be relieved by surgery. However, it is desirable to reduce the circumstances for which major surgeries are required to address stenosis.
Accordingly, it is desired to develop procedures and implants for surgically addressing stenosis through minimally invasive procedures, and preferably such surgical procedures can be performed on an outpatient basis.
U.S. Pat. No. 7,101,375 is incorporated herein by reference.